INHERITANCE CAIE BIOLOGY Flashcards
What is sexual reproduction?
A sexual reproduction is a reproduction that involves the fusion of haploid female gamete(egg) and a haploid male gamete(sperm) to produce a zygote.
What’s a Gamete?
A gamete is a reproductive cell or a sex cell.
What are haploid cells?
Haploid contains one complete set of chromosome and has a symbol “n”.
H = n
What are diploid cells?
Diploid cells contains two complete sets of chromosome and has a symbol of “2n”.
Diploid = 2n
What’s a zygote?
A zygote is form from the fusion of two gametes.
What are Homologous Chromosomes?
Homologous Chromosomes are two chromosomes that have the same gene (are similar in structure) and in the same position.
Why must the number of chromosomes halved before fertilization?
The number of chromosomes are half from diploid to haploid so that when the gametes fuse the during fertilization the diploid number will be restored (46). If not the number of chromosome will be double in the next generation.
What is the name of the term “reduction division of cells”?
Meiosis
What is a gene?
A gene is the section of the DNA that codes for protein.
how may crossing over lead to variation?
During meiosis1 the crossing over between the chromatids of the homologous chromosomes occur. Loci are exchange. this creates combinations of alleles and leads to genetic variation.
Importance of random fusion of gametes and meiosis.
Random Fusion of gametes: increases genetic variation due to the combination of chromosomes.
Meiosis: a reduction division of cells, forms the basics of sexual reproduction, and genetic variation.
How may random assortment increases genetic variation?
During metaphase 1 of meiosis 1 the bivalent chromosomes are randomly arranged are at the equator. The daughter cells will be mix and hence increases genetic variation.
What is a Locus?
A locus is the position of a gene on a chromosome.
What is an allele?
An allele is an alternative form of a gene that codes for a protein.
Explain the term “multiple alleles”
Multiple alleles is when two or more alleles codes for the same genes
