WAEC 2024 BIOLOGY OBJ ANSWERS
WAEC 2024 Biology
1-10:CCCBBBABAC
11-20:CCABDBAADD
21-30:BDADDABABA
31-40 ACCAAABCCD
41-50 BCDCADCBCA
COMPLETED
BIOLOGY ANSWERS
(3ai)
(i) The meat may turn dark brown or grey as it starts to spoil.
(ii) A strong, unpleasant smell of decay will likely develop due to bacterial decomposition.
(iii) The meat may become slimy and sticky as bacterial and enzymatic activities break down the tissues.
(iv) Visible mold or fungal growth may appear on the surface of the meat.
(3aii)
Decomposition
(3aiii)
(i) Refrigeration – Low Temperature
(ii) Salting – Dehydration and Osmosis
(iii) Smoking – Dehydration
(iv) Canning – Sterilization
(3aiv)
(PICK ANY TWO)
(i) Temperature (warmth)
(ii) Humidity (high moisture)
(iii) Oxygen (Presence of air)
(iv) Microorganisms (bacteria, fungi, etc.)
(3b)
(i) Dired maize grains: Storage in airtight containers or silos
(ii) Fresh tomatoes: Refrigeration
(iii) Veetables: Freezing
(iv) Beans: Canning
(v) Milk: Pasteurization
(4ai)
| Cell | Type…| Set of.|
|———–|——–|———-
|Onion cell | Mitosis| Diploid
|Sperm cell | Meiosis| Haploid
|Pollen grain| Meiosis| Haploid
|Ovum | Meiosis| Haploid
|Guard cell | Mitosis | Diploid
|Cheek cell | Mitosis | Diploid
(4aii)
(PICK ANY ONE)
Mitosis is the process of cell division wherein the chromosomes replicate and get equally distributed into two daughter cells.
OR
Mitosis is a process of cell division where a single cell divides into two identical daughter cells. It is crucial for growth, development, and tissue repair in organisms.
(4b)
(PICK ANY ONE)
Parents with blood groups A or B can have an offspring with blood group O if both parents carry one recessive allele for blood type O. When each parent passes on the O allele to their child, who receives one from each parent, the child’s genotype would be OO, resulting in blood group O. This is possible due to the Mendelian inheritance pattern where the O allele is recessive to both A and B alleles.
OR
For parents with blood groups A or B to have an offspring with blood group O, both parents must carry at least one recessive O allele (i.e., genotype AO or BO). When these parents produce offspring, there is a chance that they can pass on their O allele to the child. If the child receives an O allele from each parent, they will have blood group O, as the O allele is recessive to both A and B alleles.
(4c)
(PICK ANY ONE)
Genes drive evolution by passing on hereditary traits across generations. Mutations create genetic diversity within populations, providing the raw material for natural selection to act upon. Natural selection favors advantageous traits, leading to evolutionary changes over time. Additionally, genetic drift and gene flow further shape the genetic makeup of populations, contributing to the diversity and adaptation of species.
OR
Genes are the units of heredity passed from parents to offspring. Through mutation, genetic variation arises, leading to diversity within populations. Natural selection acts on these variations, favoring traits that enhance survival and reproduction. Over time, advantageous traits become more common in a population, driving evolutionary change. Genes encode the traits that are subject to selection, shaping the adaptation and evolution of species.
