B1 Science Flashcards
living organisms contain genetic material. Genetic material contains instructions that control how cells and organisms develop and function.
All the genetic materlal of a cells the organism’s_______
Genome
Are plant cells eukaryotic and do they have nucleus?
Yea
Where is the genetic material or dna stored ?
Nucleus
Name some organelles that both plant and animal cells have
Cell membrane
Ribosome
Nuclears
Cytoplasm
Mitochondria
Examples of eukaryotic cells
Plants and animal cells
Name Organelles that are in plant cells and not in animal cells
Cell wall
Vacuole
Chloroplast
Prokaryotic cells do not contain ?
Nucleus
Where are the genetic materials or dna stored in eukaryotic and prokaryotic cells ?
Eukaryotic cells-nucleus
Prokaryotic-they store freely or in loops called plasmid
Do prokaryotic cells have organelles(E.g vacuole,mitochondria) ?
No
Example of prokaryotic cells ?
Bacteria
What is a dna ?
It is a polymer (long chain) of nucleotide
Structures of a dna
Has two strands
Nucleotide pair up
Double helix shape
How do you prepare a microscope slide ?
•Add a thin layer of the specimen in the slide
•Add a drop of stain to make the part of the cell more visible
..Cover with a cover slip
How to use a microscope
Select the lowest objective lens
.Place the slide on the microscope stage
.Adjust the coarse focus until you see a rough image
.Slowly adjust the focus until you see a sharply focused image
.Repeat with higher objective lenses
How to calculate magnification and total magnification
Mag=size of image/real size of image
Total mag=eyepiece lens x objective lens magnification
What is a chromosome ?
A long strand of dna found in the nucleus in eukaryotic cells
What is a gene ?
A section is dna that contains instructions for making proteins
What is a genetic variant ?
Different versions of genes
What are alleles ?
The two copies of gene in a pair of chromosomes
What is a genotype ?
it’s an organism created by the combination of alleles
B-the dominant alleles
b-represents recessive alleles
BB is called homozygous dominant
Bb is called heterozygous
bb is called homozygous recessive
What is a phenotype ?
It’s the result of the organism’s genome and interaction with the
environments.
Most phenotypes are actually the
result of several ditterent genes working together.
What can be used when phenotypes are caused by a single gene ?
Punnets squares
What are gametes ?
Gametes have half the number of chromosomes compared to body cells.
When the sperm cell fertilises the egg, the resulting cell has the correct number of chromosomes for a body cell.
How can sex be determined?
A human individual’s sex male or female) is determined by the
Inheritance of the SRY gene on the Y chromosome that triggers the development of testes
XX chromosomes = female
XY chromosomes = male
