In the case of multicellular animals we find there are two kinds of sex cells: the female sex cell (ovum, or egg), derived from an oocyte (immature egg), and the male sex cell (spermatozoon or sperm), derived from a spermatocyte. Eggs are produced in ovaries; sperm, in testes. Both the egg and the sperm contribute to the development of the new individual; each providing one set of genes, thereby restoring the diploid number of chromosomes in the fertilized egg. The sperm possesses a whiplike tail (flagellum) that enables it to swim to the egg to fertilize it. In most cases the egg, a stationary, spherical cell, provides the potential offspring with a store of food materials, or yolk, for its early development. The term yolk does not refer to any particular substance but in fact includes proteins, phosphoproteins, lipids, cholesterol, and fats, all of which substances occur in various proportions in the eggs of different animals. In addition to yolk, eggs accumulate other components and acquire the structure necessary for the development of the new individual. In particular the egg acquires polarity—that is, the two ends, or poles, of the egg become distinctive from each other. At one pole, known as the animal pole, the cytoplasm appears to be more active and contains the nucleus (meiotic divisions occur in this region); at the other, called the vegetal pole, the cytoplasm is less active and contains most of the yolk. The general organization of the future animal is closely related to the polarity of the egg.
Record
Recording 00:00
Commenting has been turned off for this post.
Categories
- Sustainability
- Home
- Wellness
- Theater
- Sports
- Shopping
- Religion
- Party
- Other
- Networking
- Music
- Literature
- Art
- Health
- Gardening
- Games
- Food
- Fitness
- Film
- Drinks
- Dance
- Crafts
- Causes
Read More
The Hidden Power: Uncovering Ancient Secrets
**"The Hidden Power: Uncovering Ancient Secrets"** follows a daring exploration into forgotten...
Positivity
Be positive be happy in your life can become bright and shine and money runs towards you are not...
Children's Day
1. Children's Day is a special occasion dedicated to honoring children and celebrating their...
THE GRANDFATHER PARADOX
THE GRANDFATHER PARADOX
The grandfather paradox is an example of a problem arising from...
Save trees
Essay on Save Trees: Save trees is a slogan used to motivate people to save trees and plant more...
×
Your daily access limit has been reached. Please try again tomorrow.
© 2025 GoSharpener Pvt.Ltd.
Refund and Cancellation policy - We do not entertain any refunds and cancellation
Refund and Cancellation policy - We do not entertain any refunds and cancellation