Grey crescent is the area
at the point of entry of sperm into ovum
just opposite to the site of entry of sperm into ovum
at the animal pole
at the vegetal pole
The Correct Option is B
Solution and Explanation
The gray crescent is a structural feature that emerges on the side of a frog egg opposite to where the sperm enters. This region contains a cluster of growth factors that essentially control the determination of specific body parts during development. It represents a cortical area in newly fertilized frog eggs, as well as in certain salamanders, forming shortly after fertilization on the side opposite to where the sperm penetrates.
So, the correct option is (B): just opposite to the site of entry of sperm into ovum
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Concepts Used:
Infertility
Infertility is described as not being able to get pregnant in spite of having frequent, unprotected sex for not less than a year for most couples. Infertility may result from an issue with either you or your partner or a combination of factors that stops a pregnancy.
Symptoms:
The major symptom of infertility is not getting pregnant. There may be no other apparent symptoms. Sometimes, women with infertility may have irregular or missing menstrual periods. In some cases, men with infertility may have some signs of hormonal issues, like changes in hair growth or sexual function.
Causes of male infertility:
- Abnormal sperm production or function
- Problems with the delivery of sperm
- Overexposure to certain environmental factors
- Damage related to cancer and its treatment
Causes of female infertility
- Ovulation disorders
- Uterine or cervical abnormalities
- Fallopian tube damage or blockage
- Endometriosis
- Primary ovarian insufficiency
- Pelvic adhesions
- Cancer and its treatment.