Biology Flashcards
(37 cards)
What does DNA stand for?
Deoxyribonucleic Acid
DNA is the molecule that carries genetic instructions used in growth, development, and reproduction.
What is the shape of DNA?
A double helix (twisted ladder)
The double helix structure was discovered by James Watson and Francis Crick.
What are the 4 DNA base pairs?
Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
These base pairs form the rungs of the DNA ladder.
Where is DNA stored in a cell?
In the nucleus
The nucleus is a membrane-bound organelle found in eukaryotic cells.
How many chromosomes does a human body cell have?
46 (23 pairs)
Humans inherit 23 chromosomes from each parent.
What is the function of the nucleus?
It stores genetic information (DNA)
The nucleus also regulates gene expression and cell division.
Plant vs animal cells — one key difference?
Plant cells are in a more rectangualr and box-like shape. Animal cells are in a round circular shape.
Animal cells have lysosomes and centrioles, which plant cells lack.
What is mitosis?
Type of cell division that makes two identical cells and help replace your damage and old cells.
Mitosis is crucial for growth and tissue repair.
What are the 5 stages of mitosis?
Interphase, Prophase, Metaphase, Anaphase, Telophase, (IPMAT)
Each stage plays a critical role in the accurate division of chromosomes.
Why is mitosis important?
For growth and healing (It is great for repair and damage)
Mitosis allows organisms to grow and replace dead or damaged cells.
What is the difference between mitosis and meiosis?
Mitosis makes 2 identical cells; meiosis makes 4 different sex cells
Meiosis is essential for sexual reproduction.
When does the body use meiosis?
To make sperm and egg cells for reproduction.
What is asexual reproduction?
Requires only one organsim (Parent) & results a genetically identical offspring.
Name 3 methods of asexual reproduction
Budding, binary fission, spores
These methods are common in organisms like yeast, bacteria, and fungi.
What is sexual reproduction?
2 parents combine DNA to make offspring
It increases genetic variation among offspring.
What’s a zygote?
A fertilized egg (sperm + egg)
The zygote undergoes cell division to develop into an embryo.
What is cross-pollination?
Pollen from one plant fertilizes another plant
Cross-pollination enhances genetic diversity in plants.
What are the male parts of a flower?
Anther and filament (stamen)
The stamen is responsible for producing pollen.
What are the female parts of a flower?
Stigma, style, ovary (pistil)
The ovary contains ovules, which develop into seeds after fertilization.
What is a trait?
A feature you inherit (like eye color)
Traits are determined by genes and can be dominant or recessive.
What’s the difference between dominant and recessive traits?
Dominant shows up (A), recessive is hidden (a)
Dominant traits mask the expression of recessive traits in heterozygous individuals.
What is a genotype?
A genotype is the genetic code or set of genes an organism has.
It shows the combination of alleles (letters) for a trait.
What is a phenotype?
The physical appearance (like brown eyes)
It’s how the genotype shows up on the outside.
What is a Punnett square?
A tool to predict offspring traits
It shows the probability of different genotypes in the offspring.
