Term
| What happens during asexual reproduction? |
|
Definition
| A single animal produces offspring, usually through repeated mitotic cell divisions in some part of its body. The offspring are genetically identical. |
|
|
Term
| What happens in sexual reproduction? |
|
Definition
| Two haploid cells, sperm and egg, fuse to produce a diploid fertilized egg which undergoes repeated mitotic cell divisions to produce offspring. It is not genetically identical to either parent. |
|
|
Term
| Where are sperm produced? |
|
Definition
|
|
Term
|
Definition
| Diploid cells lining the walls of the seminiferous tubules, that gives rise to a primary spermatocyte. They form two types of daughter cells - one cell remains a spermatogonium and the other is committed to spermatogenesis. |
|
|
Term
|
Definition
| The process by which sperm cells form. |
|
|
Term
|
Definition
|
|
Term
| How many sperm are produced for every primary spermatocyte that undergoes meiosis? |
|
Definition
|
|
Term
| What happens to the cytoplasm when spermatids differentiate into sperm? |
|
Definition
| Most of it disappears and the haploid nucleus nearly fills the head. |
|
|
Term
|
Definition
| Contains enzymes that will dissolve protective layers around the egg. |
|
|
Term
|
Definition
| Provides the energy needed to move tail (mitochondria; ATP) |
|
|
Term
|
Definition
|
|
Term
| When does sperm production begin in human males? |
|
Definition
|
|
Term
| What is oogenesis? In which female body par does oogenesis occur? |
|
Definition
| It is the formation of egg cells, and it takes place in the ovaries. |
|
|
Term
|
Definition
|
|
Term
| What is a polar body and how does it form? |
|
Definition
| A small cell containing a nucleus but virtually no cytoplasm, produeced by both the first meiotic division (primary oocytes) and 2nd meiotic division (end oocyte). |
|
|
Term
| What is the result of oogenesis? |
|
Definition
| The result is one primary oocyte, one secondary oocyte (egg), four polar bodies (if egg not fertilized). If it is fertilized, one egg and four polar bodies are formed. |
|
|
Term
| When do oogonia form in a female's lifetime? |
|
Definition
| Sixth week of embryonic development. |
|
|
Term
| When do primary oocytes form in a female's lifetime? |
|
Definition
| 20th week of embryonic development. |
|
|
Term
| When do secondary oocytes form in a female's lifetime? |
|
Definition
|
|
Term
| When do eggs form in a female's lifetime? |
|
Definition
|
|
Term
| What is the function of the corona radiata and zona pellucida? |
|
Definition
| The corona radiata and zona pellucida form barriers between the sperm and the egg (corona radiata is first barrier, zona pellucida is second barrier). |
|
|
Term
| How does a sperm penetrate the egg? |
|
Definition
| The sperm releases and enzyme that helps them digest their way through the corona radiata and zona pellucida to reach the oocyte. |
|
|
Term
| What occurs when the first sperm contacts the surface of the egg? |
|
Definition
1. The plasma membranes of egg and sperm fuse, and the sperm's head is drawn into the egg's cytoplasm.
2. Vesicles near the surface of the egg release chemicals into the zona pellucida that reinforces it and prevents additional sperm from entering.
3. The egg undergoes meiosis II.
4. Fertilization as the haploid nuclei of sperm and egg fuse, forming a diploid nucleus. |
|
|
Term
| When does fertilization actually occur? |
|
Definition
| When the haploid nuclei of sperm and egg fuse. |
|
|
