Makin' Babies Flashcards
What are the two types of reproduction?
Asexual and Sexual
What are 4 types of asexual reproduction?
Binary fission, budding, fragmentation, and parthenogensis.
Describe binary fission.
AKA Mitosis, during binary fission, DNA doubles and then the cell splits. This type of reproduction is generally done by those in the kingdom Monera and Protoctista.
Describe budding.
Much like binary fission, but with an unequal distribution of cytoplasm.
Describe Fragmentation.
The ability to grow back body parts that are removed. Not a primary form of reproduction.
Describe parthenogenesis.
Female lays an egg that does not require fertilization. This results in clones.
What are some benefits of asexual reproduction?
It takes less energy than sexual reproduction, and it is relatively faster.
What are some cons of asexual reproduction?
Genetic diversity is low, and mutations must, therefore, be relied upon in the event of an environmental change.
What is sexual dimorphism?
A characteristic of sexual reproduction. It describes the need for there to be different gonads between the parties partaking in sexual reproduction.
What is external fertilization?
Fertilization that occurs outside of the body.
What is internal fertilization?
Fertilization that occurs inside the body. This requires reproductive structures.
What is a benefit of sexual reproduction?
Instant variation.
What is a con of sexual reproduction?
Both time and energy are required.
What functions of the penis?
- It acts as the male reproductive structure
- It acts as the sperm delivery structure
- It is used for both reproduction and excretion
How long is the average male urethra?
20 cm
What surrounds the urethra in the penis?
The corpus spongiosum.
What is the function of the corpus spongiosum?
It keeps the urethra open during an erection.
What surrounds the corpus spongiosum?
The corpus cavernosum.
What is the function of the corpus cavernosum?
It fills with blood and creates the errection.
What is done by the nervous system to create an erection?
The parasympathetic nervous system relaxes all of the sphincters in the capillary beds that reside in the erectile tissue.
What is the proper term for foreskin?
Prepuce
What are the male gonads?
The testicles or testes.
What temperature is optimal for the production of sperm?
2 degrees celsius below body temperature (around 35 degrees celsius).
What is the function of the ligaments on the inner wall of the scrotum?
This allows the testes to be contracted closer to the body, a function to keep them warm in the cold.
What length of seminiferous tubules can be found in human testicles?
250 metres
What type of cell is found in the outermost layer of the seminiferous tubules?
Spermatogonia or first degree spermatocytes.
In the seminiferous tubules, _____ undergoes meiosis to become ____, which becomes _____, which finally becomes ______.
Spermatogonia, second degree spermatocytes, spermatids, sperm.
Why do spermatogonia sometimes undergo meiosis, and sometimes undergo mitosis?
Meiosis to produce sperm, mitosis to produce other spermatogonia.
What support cell is found in the outer layer of the seminiferous tubules?
Sertoli cells.
What is the function of Sertoli cells?
- Provide nutrients
- Remove waste
- Protect sperm from immune system
How long does sperm stay in the seminiferous tubules?
About 2 weeks.
Where is the nucleus found in the sperm?
In the head, aka the main body or soma.
What enzyme is found on the head of the sperm, and what is its function.
Acrosome.
It is used by the sperm to get through the wall of the ova.
What is found in the midpiece of the sperm?
Mitochondria.
What is the function of the binding sites on the head of the sperm?
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