ANIMAL REPRODUCTION & DEVELOPMENT Dr Ilma • The two earthworms in this picture are mating • Each worm produces both sperm and eggs, which will fertilize – And in a few weeks, new worms will hatch Asexual And Sexual Reproduction • Both occur in the animal kingdom • Asexual reproduction is the creation of new individuals – Whose genes all come from one parent • Sexual reproduction is the creation of offspring – By the fusion of male and female gametes to form a zygote Mechanisms of Asexual Reproduction • Many invertebrates reproduce asexually by fission – The separation of a parent into two or more individuals of approximately the same size Mechanisms of Asexual Reproduction • Budding – In which two new …show more content…
Sperm form in the testes, pass through the sperm duct (vas deferens), and are stored in the seminal vesicle. The male ejaculates sperm along with fluid from the accessory glands. (Males of some species of insects and other arthropods have appendages called claspers that grasp the female during copulation.) Accessory gland (b) Vagina Female honeybee. Eggs develop in the ovaries and then pass through the oviducts and into the vagina. A pair of accessory glands (only one is shown) add protective secretions to the eggs in the vagina. After mating, sperm are stored in the spermatheca, a sac connected to the vagina by a short duct. Female Reproductive System • The female external reproductive structures include – The clitoris – Two sets of labia • The internal organs are a pair of gonads – And a system of
The female reproductive system contains two ovaries. The ovaries nourish the eggs as they mature and are ready for fertilization. An egg will come to maturity approximately every 28 days. When the ovum has matured, the ovary releases it in a process called ovulation. After ovulation the ovum moves into the fallopian tube adjacent to the ovary.
Caenorhabditis elegans, a type of free-living nematode that is found in soil, is the subject matter for this experiment (Marsh). C. elegans allow for an exceptional model organism because it is easily raised in the laboratory setting, it reproduces rapidly, has a short life cycle of 3 days where it develops from egg to adult worm, only 1.3mm in length, and although only having 959 somatic cells, it shares many characteristics with other multicellular organisms like having organs and a nervous system (Kaletta). These nematodes can either be a self-fertilizing hermaphrodite where each animal produces both sperm and egg, or they can be males that will mate with the hermaphrodites (Brenner). When a hermaphrodite self-fertilizes, the chance of having a male being produced is extremely low at just 0.1%, however, when a hermaphrodite is fertilized by a male, the ratio of males to hermaphrodites is generally equal making it 1:1 (Altun).
Fertilization in animals is similar to that in plants because its first cellcell change occurs after gamete fusion rises in the cytoplasmic Ca2+ levels as it does in animal gamete fusion. Also, the plants make a block to polyspermy, which is the fertilization of an egg by more than one sperm cell, as do the animal’s cell’s eggs.
Every species has their unique way to survive and interact with their environment. Some have extra appendages in order to better combat predators, or they have bodies that allow them to camouflage to their environment. Every species also has their way of reproducing and copulation, whether for necessity or for enjoyment. Two species with different mating habits are the Apis mellifera, better known as honey bees, and Pan paniscus, Bonobos apes. The former uses its reproduction methods for the survival of the entire colony of honey bees in exchange with the death of few and the former uses copulation in a social setting in order to keep the peace of the pack.
In insect species with indirect sperm transfer, sperm is packed in a spermatophore that is either externally attached to the female 's genital opening or introduced into her bursa copulatrix. Sperm transfer is not immediate in these species, and consequently mate guarding has been suggested to function as a mechanism of guarding sperm until it is released from the spermatophore into the female (i.e. spermatophore guarding). Spermatophore guarding is relatively common in insect species with external spermatophores (e.g. Orthoptera; Alcock 1994; Simmons 2001), but supposedly absent in species with internal spermatophores and rapid sperm release (Simmons 2001). This study focuses on two hypothesis associated with mate guarding a tactic of many species that adjust their reproductive behaviour according to the apparent risk of sperm competition. The phenomenon of mate guard to consider sperm competition levels and evolution of internal spermatophore guard is wide spread in insects and other animals. We analyse two hypothesis one the rival exclusion followed by the next spermatophore renewal hypothesis. Results showed that as rival was introduced to the arena of mating of the distinctive original male (guard) in many cases showed a strong aggressive behaviour regardless of whether successively avert the rival. In the second hypothesis certainly majority of the incidents showed an attempt of
As researched, earthworms are known as hermaphrodites, which are defined as an animal having both male and female sex organs or other sexual characteristics, either abnormally or (in the case of some organisms) as the natural condition (Dictionary). During the earthworm lab, I discovered that earthworms have both seminal vesicles and seminal receptacles. Holding sperm after cross-fertilization has occurred is the seminal receptacles for females only. Seminal vesicles produce and release sperm and are well known as the male reproductive organs. Gizzards are responsible for mechanical digestion and grinding up the food for earthworms (Earthworm dissection video). On the other hand, for male crayfish to make sperm they must contain testes, unlike the females they
Judson contributes to onefs understanding of sex among different organisms in that she makes difficult concepts simple to comprehend. Although she uses scientific terminology, she limits it so that anyone can understand the technical information she shares. Judson also describes the types of environments in which each species and
The reproductive system is a system of sex organs within an organism which work together for sexual reproduction. The development of the reproductive system is controlled by the pituitary
17) The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called
There are many methods of reproduction, but the two main methods are sexual and asexual, but which one is more efficient or beneficial. Sexual reproduction is the fusing of two gametes to produce an offspring. This form of reproduction is used by a lot of organisms, including us. Asexual reproduction is reproduction that only involves one parent. (“Pros and cons of sexual and asexual reproduction”). I am going to focus on asexual reproduction and the Desert Grassland Whiptail Lizard. This unique lizard uses asexual reproduction. Asexual reproduction is better for this species of lizards because it only requires one parent, it is less risky, and the population is only female.
The Female Reproductive System parts are gametes, which is a mature haploid male or female germ cell that is able to unite with another of the opposite sex in several reproductions to form a zygote. Egg is a person possessing a specified quantity. Ovum is a mature female reproductive cell especially of a human or other animal that van divide to give rise to an embryo usually only after fertilization by a male cell. Vaginal is a muscular tube leading from the external genitals to the cervix of the uterus in women and most female mammals. Labia is the inner and outer folds of the vulva, at either side of the vagina. Clitoris is a small sensitive and erectile part of the female genitals at the anterior end of the vulva. Urethra is a duct by
Octopuses reproduction is sexual and takes place in the somewhat shallow depths of 25 -100m and can last hours. The fertilization process begins with the male octopus, he uses his third right tentacle which
Sex is a mode of reproduction and a way for a large number of organisms to reproduce. But is sexual reproduction really advantageous? There are advantages and disadvantages to sexual reproduction.
Martin, after careful consideration and researching in unique methods, comes to an overall conclusion that there are cultural influences in the way egg and sperm interactions are presented in textbooks. This conclusion has many serious
sperm as a superior and the egg as an expelling organ part. Moreover, the features of the egg and