Zygotene is a stage of chromosome pairing. The homologous chromosomes (maternal and paternal chromosomes) come closer and start pairing together... View Article
The importance of meiosis goes beyond maintaining chromosome number from one generation to the next. Meiosis also builds genetic variability in a... View Article
If gametes contained the same number of chromosomes as other body cells, the chromosome number would double with each generation. For humans,... View Article
Reproduction is one of the basic traits of life. Most multicellular organisms reproduce sexually. This involves the production of gametes wherein... View Article
Cleavage is not possible in plant cells as their rigid cell walls cannot be pulled inwards. As a result, in the plant cells, cytokinesis starts... View Article
Metaphase is identified by the fully formed spindle. Because of the heavy coiling and dehydration, the chromosomes become short and thick with... View Article
Simultaneous with the changes in the cytoplasm, the chromatin network of the nucleus becomes distinctly visible as chromosomes. They eventually... View Article
The animal cell in the first stage of karyokinesis, almost doubles in size and typically becomes round as the cytoplasm becomes heavier and more... View Article
Direct cell division or amitosis is a means of asexual reproduction in unicellular organisms such as protozoans. In this type of reproduction,... View Article
Interphase lasts for a longer duration during which the following events occur - Chromosomal DNA duplicates and each chromosome is composed of... View Article
Every chromosome has highly organized ends known as telomeres. They have a specific role in maintaining the individuality and stability of... View Article
Some of the chemoautotrophs must have eventually developed chlorophyll like pigments by using magnesium porphyrin of the oceanic water. Such... View Article
A karyotype is the set of chromosomes contained in the nucleus of a species. It discloses the size, number, shape and type of chromosome. This... View Article
Based on the position of the centromere, chromosomes can be classified as follows - Type of chromosome Shape assumed Position of centromere... View Article
The phenomenon of the occurrence of more than two haploid sets of chromosomes in a species is called polyploidy. It involves the multiplication... View Article
The role of the centrosome is as follows - Centrosomes play an important role in cell division. Centrioles during cell division move apart and... View Article
Reproducing individuals are units of natural selection. It is the gene pool of the population that is exposed to natural selection and only those... View Article
New species evolve by sudden and distinct heritable changes called mutations The first individual showing a change is called a mutant. It is... View Article
Consequent to overproduction, there is keen competition for shelter, food and mating among the newly produced individuals. This competition is... View Article
