Animal Form and Function: Reproduction

mes (67)in DTube • 6 days ago

In this video I go over a quick review of animal reproduction, which can be done in two ways: asexual or sexual. Nearly all animals engage in some form of sexual reproduction, where haploid gametes (motile spermatozoa and stationary ova) merge to create diploid zygotes, which then develop into a hollow sphere called a blastula. Most animals then invaginate to form a gastrula with a digestive chamber and two or three separate germ layers, which later differentiate to form tissues and organs.

Some animals undergo asexual reproduction, which don't involve the fusion of gametes or the change in the number of chromosomes, often times resulting in a genetic clone. An example is the incredible Hydra which reproduces via fragmentation by budding out into a new Hydra. The Hydra do not appear to die of old age, or age at all, and can regenerate even if chopped up into pieces! 🤯

#science #biology #reproduction #animals #hydra

Timestamps:

Animals can reproduce either sexually or asexually: 0:00
Invagination is the folding of an area of exterior cells towards the inside of the blastulla: 1:55
Image of sexual reproduction in dragonflies: 2:45
Some animals undergo asexual reproduction, which doesn't involve the fusion of gametes or change in the number of chromosomes, and often times creates a genetic clone: 3:00
Hydra don't appear to die of old age or age at all, and have regenerative ability: 4:22
Cnidocyte is an explosive cell containing one giant secretory organelle that can deliver a sting to other organism: 5:06

Full video below: