Ch. 4 Genetics Flashcards
How many pairs of unique, non homologous chromosomes do human diploid cells have? How many total is that?
23 pairs (including 1 sex chromosome pair- eg. xy pair)
46 total chromosomes
Roughly how many genes are on a chromosome?
100-1000
What is a gene?
A specific section of a chromosome/DNA that codes for a particular trait.
What is the location of a gene on a chromosome called?
Locus
“In most multicellular organisms, the chromosomes appear in _____ (_____ or polyploid)
Sets
Diploid
New cells come only from _____________ cells by cell division.
Pre-existing
Genetics: the study of ____ and ____.
Heredity and variation
What are the important steps to cloning an animal?
- Remove an unfertilized egg for one female, and removes its nucleus.
- Run electrical current through it, along with with another animals cell such as skin cell. This will fuse the two cells into one, with the DNA of the animal to be clones.
- This is placed inside the surrogate mother as it begins dividing to many cells and into an embryo.
What are main steps to cloning a plant?
- Remove a plant cell
- Place it in nutrient rich environment
- The cell will undifferentiate, allowing it to replicate into many different cells and grow a copy of the plant. It will have identical DNA
What are homologous chromosome?
Two chromosomes with the same genes. They don’t necessarily have same alleles/DNA sequence.
Why is genetic diversity beneficial to a population?
It allows them to adapt to change better.
Selection pressures take out the weak and leave the strong, which reproduce making more offspring with that trait.
Haploid?
A cell with only one of each chromosome. In humans this would be a cell with 23 chromosomes.
Diploid?
Cell with two of each unique chromosome number. In humans this is a cell with 46 chromosomes (most cells).
Are gametes haploid or diploid?
Haploid.
Are zygotes haploid or diploid?
Diploid.
What is the name of the cell once the egg and sperm fuse?
Zygote
What are gametes?
Sex cells. Eggs and sperm
What is synapsis during meiosis?
The crossing over of two homologous chromosome pairs during prophase which allows them to exchange segments of the chromosome and genes. This is basically random.
What is the purpose of pre-natal genetic testing?
To look for any genetic abnormalities in the fetus such as trisomies or monopsonies, or abnormal chromosome structure.
What are the pictures of chromosomes called?
Karyotypes
What is the name of non-sex chromosomes?
Autosomes
What sex chromosomes do males have?
XY
What sex chromosomes do females have?
XX
What is it called when the chromosomes don’t split to opposite sides of the cell during anaphase?
Nondisjunction.
What’s the main difference between prophase 1 and 2 in meiosis?
Prophase 1 it is a diploid cell with duplicated chromosomes (46 paired chromosomes, 92 chromatids) crossing over. Prophase 2 it is a haploid cell (23 paired chromosomes 46 chromatids). Prophase 2 also has two cells.
What’s the main difference between metaphase 1 and 2 in meiosis?
In 1, duplicated chromosomes lined up with their homologous chromosomes on the center of the cell. In metaphase 2, duplicated chromosomes line up on the center in single file. There are also two cells.
What’s the main difference between anaphase 1 and 2 in meiosis?
Anaphase 1, homologous chromosomes go opposite ways. In anaphase 2, the chromosomes two chromatids break apart and move opposite ways as individual chromosomes.
What’s the main difference between telophase 1 and 2 in meiosis?
In telophase 1, there are n paired chromosomes in each of the two emerging cell parts. In telophase 2 there are n unpaired chromosomes.
What cells are produced in meiosis in males and females.
Male: Sperm
Female: 3 polar bodies and an ovum (egg)
What are the five possible changes in chromosome structure?
Inversion, duplication, deletion, insertion, and translocation.
Cytoplasmic DNA is from ______ and/or ______
Chloroplasts and/or mitochondria.
Cytoplasmic DNA is inherited from the _________.
Mother
